The Experts below are selected from a list of 198 Experts worldwide ranked by ideXlab platform

Hany A Alfons - One of the best experts on this subject based on the ideXlab platform.

  • photovoltaic powered regulated Cathodic Protection System
    Solar Energy, 1994
    Co-Authors: Wagdy R Anis, Hany A Alfons
    Abstract:

    Abstract The Cathodic Protection (CP) System objective is to protect metallic structures against corrosion caused by chemical reaction between metallic structures and surrounding mediums, such as soil or water. To overcome such a problem, a sacrificing anode is connected to the protected structure (which acts as a cathode) through a DC power supply. As a result, a current passes from the sacrificing anode to the protected cathode. This leads to anode corrosion rather than causing the cathode (protected structure) corrosion. To stop the corrosion, the protected structure requires a constant current determined by structure metal, area, and the surrounding medium. The major difficulty in achieving this condition is the variation of surrounding medium resistivity due to climatic condition changes. For example, rains as well as humidity decrease soil resistivity, and as a result the DC current increases and a harmful overProtection may take place. Both corrosion and overProtection are harmful for the metallic structure. Conventional CP Systems resolve this problem by manual adjustment of DC voltage periodically to obtain a constant current. Such adjustment depends on the personal experience of the technician and the accuracy of the measuring equipment used. Accordingly, the adjustment is subject to personal and measuring equipment errors. Moreover, if the interval between two successive adjustments is relatively long, structure corrosion becomes significant, which may have drastic consequences. To overcome the aforementioned difficulties associated with the conventional CP System, an automatically regulated CP System is discussed in this article. The proposed System senses the variations of the surrounding medium resistivity and adjusts the DC voltage of the System automatically so that the DC current is kept constant at the required level. The design of a solar photovoltaic System to supply the CP System by the required DC power is also discussed.

  • photovoltaic powered regulated Cathodic Protection System
    Journal of Power Sources, 1994
    Co-Authors: Wagdy R Anis, Hany A Alfons
    Abstract:

    Abstract The objective of a Cathodic Protection System is to protect metallic structures against corrosion. To achieve this, a sacrificial anode is connected to the protected structure (which acts as a cathode) through a d.c. power supply. To stop the corrosion, the protected structure requires a constant current. The current is determined by the metal and area of the structure, as well as the surrounding medium. The major difficulty in achieving a constant current is the variation in the resistivity of the surrounding medium that is caused by changes in the climatic conditions. Conventional Cathodic-Protection Systems resolve this problem by manual adjustment of the d.c. voltage periodically to obtain a constant current. Such adjustment depends on the experience of the technician and the accuracy of the measuring equipment. Moreover if the interval between successive adjustments is relative long, the corrosion could become excessive. To overcome such difficulties, an automatically regulated System has been developed. The proposed System senses variations is the resistivity of the surrounding medium and adjusts the d.c. voltage accordingly so that the current is kept constant at the required level. The design of a solar photovoltaic System to supply the required d.c. power is discussed in this communication.

Wagdy R Anis - One of the best experts on this subject based on the ideXlab platform.

  • design of control circuit of solar photovoltaic powered regulated Cathodic Protection System
    Solar Energy, 1995
    Co-Authors: Wagdy R Anis
    Abstract:

    Abstract Cathodic Protection (CP) System objective is to protect metallic structures against corrosion caused by chemical reaction between metallic structures and surrounding medium such as soil or water. To overcome such a problem a sacrificing anode is connected to the protected structure (which acts as a cathode) through a d.c. power supply. The d.c. power required for CP Systems is characterized by low voltage and high current. This power may be obtained from a.c. power source, if available, and a rectifier. The second alternative is to use a diesel generator and a rectifier, but this System requires frequent fuel addition and maintenance. If the location of the System is remote, maintenance and fuel transport become costly. Recently solar photovoltaic (PV) Systems are used to provide Cathodic Protection Systems in remote areas by d.c. power. Solar PV Systems are modular so that they may be designed to operate at the required voltage and current easily. PV Systems are maintenance free. To stop the corrosion entirely, the protected structure is to be fed by a constant current determined by structure's metal, area and the surrounding medium. The major difficulty to achieve this goal is the variations of the surrounding medium resistivity due to climatic conditions changes. Conventional CP Systems resolve this problem by periodical manual adjustment of the d.c. voltage to obtain a constant current. Such adjustment depends on the experience of the technician and the accuracy of the measuring equipment used. Moreover if the interval between two successive adjustments is relatively long, an appreciable corrosion may take place because of the non accurate d.c. voltage applied to the System. To overcome this difficulty, an automatically regulated CP System is discussed by Anis and Alfons [Solar Energy, 53(2), pp. 211–214, 1994]. The proposed System senses the variations of surrounding medium resistivity and adjusts the d.c. voltage of the System automatically so that the d.c. current is kept almost constant at the required level regardless of soil resistivity variations. In this work the design of the electronic control circuits of the regulated CP System is thoroughly investigated.

  • photovoltaic powered regulated Cathodic Protection System
    Solar Energy, 1994
    Co-Authors: Wagdy R Anis, Hany A Alfons
    Abstract:

    Abstract The Cathodic Protection (CP) System objective is to protect metallic structures against corrosion caused by chemical reaction between metallic structures and surrounding mediums, such as soil or water. To overcome such a problem, a sacrificing anode is connected to the protected structure (which acts as a cathode) through a DC power supply. As a result, a current passes from the sacrificing anode to the protected cathode. This leads to anode corrosion rather than causing the cathode (protected structure) corrosion. To stop the corrosion, the protected structure requires a constant current determined by structure metal, area, and the surrounding medium. The major difficulty in achieving this condition is the variation of surrounding medium resistivity due to climatic condition changes. For example, rains as well as humidity decrease soil resistivity, and as a result the DC current increases and a harmful overProtection may take place. Both corrosion and overProtection are harmful for the metallic structure. Conventional CP Systems resolve this problem by manual adjustment of DC voltage periodically to obtain a constant current. Such adjustment depends on the personal experience of the technician and the accuracy of the measuring equipment used. Accordingly, the adjustment is subject to personal and measuring equipment errors. Moreover, if the interval between two successive adjustments is relatively long, structure corrosion becomes significant, which may have drastic consequences. To overcome the aforementioned difficulties associated with the conventional CP System, an automatically regulated CP System is discussed in this article. The proposed System senses the variations of the surrounding medium resistivity and adjusts the DC voltage of the System automatically so that the DC current is kept constant at the required level. The design of a solar photovoltaic System to supply the CP System by the required DC power is also discussed.

  • photovoltaic powered regulated Cathodic Protection System
    Journal of Power Sources, 1994
    Co-Authors: Wagdy R Anis, Hany A Alfons
    Abstract:

    Abstract The objective of a Cathodic Protection System is to protect metallic structures against corrosion. To achieve this, a sacrificial anode is connected to the protected structure (which acts as a cathode) through a d.c. power supply. To stop the corrosion, the protected structure requires a constant current. The current is determined by the metal and area of the structure, as well as the surrounding medium. The major difficulty in achieving a constant current is the variation in the resistivity of the surrounding medium that is caused by changes in the climatic conditions. Conventional Cathodic-Protection Systems resolve this problem by manual adjustment of the d.c. voltage periodically to obtain a constant current. Such adjustment depends on the experience of the technician and the accuracy of the measuring equipment. Moreover if the interval between successive adjustments is relative long, the corrosion could become excessive. To overcome such difficulties, an automatically regulated System has been developed. The proposed System senses variations is the resistivity of the surrounding medium and adjusts the d.c. voltage accordingly so that the current is kept constant at the required level. The design of a solar photovoltaic System to supply the required d.c. power is discussed in this communication.

J C Joshi - One of the best experts on this subject based on the ideXlab platform.

P R Mishra - One of the best experts on this subject based on the ideXlab platform.

Sanja Martinez - One of the best experts on this subject based on the ideXlab platform.

  • Modelling of the Cathodic Protection System with dynamic non-linear polarization characteristics
    2015 XXV International Conference on Information Communication and Automation Technologies (ICAT), 2015
    Co-Authors: Adnan Mujezinović, Irfan Turković, Sanja Martinez, Slobodan Milojković
    Abstract:

    Cathodic Protection (CP) is a technique that is used for Protection of underground and underwater metallic structures from corrosion. Design of Cathodic Protection System requires defining of Protection current density and potential. These parameters must meet given criterions during the exploitation of Cathodic Protection System. This paper deals with problem of modelling of the Cathodic Protection Systems with dynamic non-linear polarization characteristics. Firstly, paper describes dynamic non-linear polarization characteristics. Mathematical model based on combined Boundary Element Method and Finite Difference Time Domain Method with assumptions on which is based are explained in the following part. Finally, application of the presented mathematical model was done on one geometrically simple example.

  • disbonding of underwater cured epoxy coating caused by Cathodic Protection current
    Corrosion Science, 2009
    Co-Authors: Sanja Martinez, Lidija Valek žulj, Frankica Kapor
    Abstract:

    Abstract Cathodic disbonding of the underwater-applied, ultra-thick, solvent free epoxy coating subjected to various levels of Cathodic Protection was investigated during the period of the coating cure. The results indicate that the partially cured coating was of low resistivity, between 10 3 and 10 5  Ω cm 2 for the Cathodic polarization of on-potentials between −0.98 and −1.4 V Ag/AgCl/sw . The coating was shown to be capable of withstanding normal levels of Cathodic Protection between off-potentials of −0.8 and −1.1 V Ag/AgCl/sw while the IR drop, introduced by the coating in the same potential range, increased from 0.06 to 0.1 V and has to be taken into account at the design stage of the Cathodic Protection System. Beneficial influence of calcareous deposit formation on the Cathodic Protection current was confirmed, particularly for the failed coating. The initial period (1 week) of coating cure was shown as the most critical for disbonding processes caused by the excessive Cathodic polarization.